We refer to our previous comments on Sibanye’s West Rand Treatment Project. We respectfully request that our previous comments be read in conjunction with the following comments.
In our previous comments, we expressed the following concerns:
- A number of cases have been identified where the re-mining of the dumps was not completed due to the lack of funding on the part of the mining company or due to the heterogeneity in the dumps which were mined.
- The granting and authorization for the reprocessing of individual residue deposits by the Department of Mineral Resources has allowed the selective extraction of value from portions of a site without ploughing some of that value back into the rehabilitation of the entire area.
- Radiometric surveys have in some cases shown elevated levels of residual radioactivity in the soils. Unrestricted development and inappropriate land-uses will exacerbate the risks to the mining industry and to the State.
We therefore recommended:
- The complete removal of the Tailings Storage Facilities (TSFs).
- Ploughing some of the value from the extraction of the gold into the rehabilitation of the entire area.
- Rehabilitation of the footprint/s.
- Soft land uses as opposed to high risk land uses such as grazing, residential developments and cropping.
- Pre-determined and agreed upon (with Interested and Affected Parties) sustainable future land use with associated resources (e.g. water).
Remobilisation of metals and the subsequent contamination of the downstream water courses
We understand from the Executive Summary of the Surface Water Assessment Report that the Millsite Complex is located within the Limpopo Water Management Area while the Cooke Plant and the Porge-, SRK- and Battery Pits are located within the Vaal Water Management Area and that the main or perennial rivers draining these areas are the Tweelopiespruit West/Bloubankspruit River and the Wonderfonteinspruit.
The associated contribution to water ingress into the mine void is likely to be considerable as the old tailings are hydraulically mined using high-pressure cannons containing mine water (Winde et al. 2011). This practice introduces air and water into anaerobic tailings, which not only contributes to acid mine drainage formation but there is also evidence for the remobilization of contaminants such as uranium and cyanides during disturbance of old tailings deposits. (Sutton & Weiersbye 2007; Winde et al. 2011).
It is anticipated that during the reclamation operations there will be the risk of contaminated runoff into the Tweelopiespruit, Bloubankspruit and the Wonderfonteinspruit downstream of the reclamation operations. According to the Integrated Water and Waste Management Plan in support of the Water Use License Application (page 140) the Millsite TSF complex also drains towards the Robison Lake. It is common cause that the Robinson Lake, the Upper Tweelopiespruit and the Upper Wonderfonteinspruit have passed their thresholds and are not in the position to receive additional loads of metals.
The Wetland Sensitivity Mapping and Impact Assessment: Freshwater Resource Assessment in the Vicinity of the Proposed Millsite Reclamation informs us that the present ecological score is in the HGM Units 1, 4 and 5 a D and an E. Notwithstanding their PES scores, we are informed that they do still provide some hydrological importance services and habitat for various species. Page 28 (Figure 8-2) identified the distribution of NFEPA wetlands (we have noted that some were incorrectly categorised as NFEPA wetlands) within the Project area. NFEPA wetlands are categorized in terms of the Mining and Biodiversity Guidelines as high risk to mining and of Highest Biodiversity Importance.
The Wetland Sensitivity Mapping and Impact Assessment Report (page v) refers to transport of tailings and contaminated soils which has the potential to result in contamination and sedimentation and furthermore, that the disturbance of historical tailings and contaminated soils has the potential to result in increased oxidation of pollutants such as pyrites, which has the potential to increase impacts to water quality of the freshwater resources in the vicinity of the Millsite TSF. In addition to the management actions and targets recommended on page 64 and 65 of the Report we wish to propose the following recommendations with supporting information.
Tweelopiespruit and wetlands
According to the Harmony Environmental Impact Document titled “Impact of the discharge of Treated Mine Water, via the Tweelopies Spruit, on the receiving Water body Crocodile River System, Mogale City, Gauteng Province”, 2654 Ha are under irrigation using borehole water within the Zwartkrans Compartment and 458 Ha are under irrigation using river water. More than 11 491 people use the water for domestic purposes.
The Tweelopiespruit’s path through the Krugersdorp Game Reserve and the Zwartkrans Compartment, which hosts the sensitive Cradle of Humankind World Heritage Site, assigns to it even greater ecological importance and sensitivity.
The above statements find support in the Integrated Water and Waste Management Plan in support of the WULA (page 104).
The decant of untreated mine water from 2002 to 2012 and the current discharge of neutralised mine water via the Tweelopiespruit have resulted in the contamination of receptor dams such as the Robinson Lake, the Hippo Dam and Aviary Dam within the Tweelopiespruit and its associated wetlands. The Dams, associated wetlands and streambed contain a yellow-orange solid colloquially known as yellow boy and other types of iron precipitates, including iron oxides and oxyhydroxides. All these precipitates discolour the water and smother plant and animal life on the streambed, disrupting stream ecosystems.
 The Surface Water Assessment Report (page iii) recommends: “Ensure that the surface profile is rehabilitated to promote natural runoff drainage and avoid ponding of water within the rehabilitated area. Surface inspection should be continuously undertaken to allow runoff to drain onto the natural streams until vegetation has fully established on the site.”
It is assumed that the runoff referred to in the above mitigation and management measure is the runoff after the footprint had been rehabilitated since there is the near certainty that runoff from the unrehabilitated footprint will contain elevated levels of sulphate, NORMs and a broad spectrum of metals.
 DWAF 16/2/7/C221/C/24 (3 December 2006)
 Coetzee et al., 2003 reported a uranium concentration in a surface-water body next to the northern watershed of the headwater region of the Wonderfonteinspruit (Robinson Lake) of 16 mg/l after underground mine water decanting into the Tweelopiesspruit was pumped into the lake. This extreme concentration is believed to be the result of remobilisation of uranium from contaminated sediment by acidic water.
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